For any term, ask two different questions:
Question 1: Does its precise conceived identity exclude application to many distinct individuals? If so, it may be a real particular.
Question 2: Is it more specific than some wider concept under which it falls? If so, it is a relative particular in that comparison.
Zayd: a specified individual falling under human — both.
Human: applicable to many and falling under animal — relative, not real.
The distinction separates the identity of an individual from the position of a species within a wider genus.